Full Moon o Sagashite (満月をさがして, Furu Mūn o Sagashite, lit. "Searching for the Full Moon") is a Japanese shōjomanga by Arina Tanemura. According to the furigana, the kanji 満月 in the title are read furu mūn ("full moon") and not mangetsu or mitsuki, the Japanese words for the full moon. In North America, the series is published as Full Moon, although the full title is given on the front cover.

The manga was published by Shueisha in the magazine Ribon from January 2002 to June 2004 and collected in seven tankōbon volumes. The manga is published in North America in English by Viz Media. The series was adapted as an anime television series produced by Nihon Ad Systems, which ended before the manga was completed, plus an OVA distributed with an issue of Ribon. The Anime series was broadcast on TV Tokyo, where it enjoyed high ratings.

The anime series was also licensed for retail release in North America by Viz Media though only the first 28 episodes were commercially released on DVD before it was discontinued.

Twelve-year-old Mitsuki Kouyama is a talented girl who dreams of becoming a singer, but she is afflicted with sarcoma, which is curable only through a surgery that could ruin her vocal cords, and lose her ability to sing. The tumor in her throat already affects her ability to breathe well and sing loudly. Her grandmother also hates music and is completely opposed to Mitsuki's wish to audition. Mitsuki's dreams seem impossible to achieve, until one day she is visited by two shinigami, whom only she could see. The shinigami, Takuto and Meroko, inadvertently tip Mitsuki off that she has only one year left to live.

Mitsuki then realizes she cannot wait any longer to fulfill her dream, so she runs away from home and the shinigami, to try to audition for a singing competition. However, the shinigami stop her before she is able to audition. She moves Takuto, the male shinigami, to agree to a compromise: If Mitsuki promises to go quietly when her year is up, he would help her become a singer, so she could leave the world with no regrets. Takuto gives her the ability to transform into a completely healthy 16-year-old, so that she could meet the age requirements of the audition, and sing without hindrance.

Despite heavy competition, Mitsuki wins over the judges with her excellent voice and her enthusiasm for singing, sealing a contract with Seed Records. To conceal her true identity, she chooses the stage name "Fullmoon".

Mitsuki had decided to become a singer two years before, when she was 10 years old. She had made a promise with Eichi Sakurai, a 16-year-old boy she met at her orphanage, that the next time they met, they would both be closer to their dreams. Eichi wanted to become an astronomer and Mitsuki wanted to become a singer. Shortly after, Eichi was adopted and emigrated to America before Mitsuki could express her feelings for him. Mitsuki hopes that by becoming a famous idol, Eichi would be able to hear her sing and realize her feelings for him. This is a tale of growing up, falling in love, awareness of life and death, and desire to move forward.